Probiotics vs. prebiotics: what you need to know

Fermenting vegetables. Woman putting cabbage and carrots in the jar, preparing them for fermentation.

What’s the difference between probiotics and prebiotics? Supplements containing them are increasingly found on store shelves. But what are they, and do you need to take one or both?

WellTuned spoke with Sarah Provence, a registered dietitian and nutritionist educator for BlueCross BlueShield of Tennessee, to find out.

“The most important thing to know is that probiotics and prebiotics work together to help support a healthy gut,” Sarah says. “And, like a lot of supplements, you can get them from healthy foods.”

Probiotics 101:

Sarah Provence: Many people have embraced probiotics to enhance their gut health, and they continue to grow in popularity. Probiotics are essentially bacteria, often referred to as “good bacteria.” They’re microorganisms that help control other bacteria in your body. They help maintain a healthy balance so you can digest food, and they help prevent pathogens from causing disease. That balance is important. For example, when you take an antibiotic, the medication targets the bacteria that’s causing your illness. At the same time, it can throw off the balance of bacteria in your gut, and you may wind up with side effects like diarrhea. Taking a probiotic can help prevent that.

You can eat foods that contain probiotics, which include fermented foods like:

  • yogurt
  • miso
  • tempeh
  • sauerkraut
  • pickles
  • kimchi
  • cheese
  • kombucha

Or you can take a probiotic supplement to add more good bacteria to your digestive tract.

What are prebiotics?

Sarah Provence: Many people are at least a little familiar with probiotics. Prebiotics are lesser known, but also growing in popularity. Prebiotics serve as the food for probiotics to work better. They support the probiotics by promoting the growth of those microorganisms.

Prebiotics are present in fiber-rich foods, such as vegetables, fruits, and whole grains. You might try eating more apples, asparagus, bananas, garlic, onions, soybeans, and wheat. They’re good sources of prebiotics and fiber. That’s a good goal, since most people don’t get enough fiber in their diets as it is.

The Academy of Nutrition and Dietetics recommends that women consume 25 grams of fiber per day, while men should try to consume 38 grams of fiber each day. However, people shouldn’t increase fiber intake too quickly. It can cause gas, bloating and constipation. Sometimes people even experience these symptoms when they start taking probiotics, too.

Both probiotics and prebiotics improve gut health

Sarah Provence: Gut health is definitely a hot topic in nutrition right now. We’re learning more all the time about how your gut microbiome plays a role in many aspects of your health. Many experts believe that the gut microbiome impacts your metabolism, your immune system, and gastrointestinal conditions. Scientists are also studying the possible connection between the gut microbiome and diseases like type 2 diabetes and obesity.

Before you buy, consider this

Sarah Provence: Most healthy adults can consume foods that contain prebiotics and probiotics. One option is to make a fruit smoothie that contains prebiotic-rich fruit and probiotic-rich yogurt.

If you’re planning to buy supplements, it’s important to know that not all supplements are created equal. Probiotic supplements, for example, contain different strains of bacteria, and different strains are associated with different benefits. There is also still not enough conclusive evidence on how much is safe or effective to take. Supplements can even contain ingredients that aren’t listed on the label, since they’re not regulated by the U.S. Food and Drug Administration (FDA) like medicine is.

I strongly encourage you to discuss any supplements with your doctor. Ask them about the type, brand, and amount before you start taking one, so you’ll be aware of any possible side effects or interactions.

More from Sarah Provence on WellTuned

Jennifer Larson

Jennifer Larson is Nashville-based writer and editor with nearly 20 years of experience. She specializes in health care and family issues.

More Posts

Get more information about specific health terms, topics and conditions to better manage your health on BlueCross BlueShield of Tennessee members can access wellness-related discounts on fitness products, gym memberships, healthy eating and more through Blue365®. BCBST members can also find tools and resources to help improve health and well-being by logging into BlueAccess and going to the Managing Your Health tab.